This invention pertains to apparatus for abstracting heat from a substance.
More particularly, the invention pertains to an improved apparatus which utilizes a matrix comprised of liquids and solids to abstract, over an extended period of time, heat from a substance.
So called xe2x80x9ccold packsxe2x80x9d are well known and typically, for example, comprise pliable, hollow, vinyl containers filled with a gelatin. In use, the cold pack is frozen and is placed against an individual""s neck or other part of the individual""s body to cool the individual. One such conventional cold pack is marketed under the trademark xe2x80x9cTHERAPACxe2x80x9d and comprises a twelve inch-by-twelve inch two ply vinyl container filled with a white odorless insoluble gelatin. Another conventional cold pack is marketed under the trademark xe2x80x9cCOLPACxe2x80x9d and comprises a twelve inch-by-twelve inch single ply polymer container filled with a gray odorless soluble gelatin. Such conventional cold packs are widely disseminated and effectively absorb heat. One principal disadvantage of such cold packs is that they have a relatively short-lived ability to stay cold. For example, when the THERAPAC and COLPAC cold packs noted above are removed from a freezer, the temperature on the outer surface of the cold pack can be five degrees F. After about an hour, the temperature can be about forty-five to fifty degrees F. After about two hours, the temperature on the outer surface of the cold packs can be about fifty-two to fifty-eight degrees F. After about three hours, the temperature can be about sixty-five to seventy degrees F. Consequently, after only an hour the temperature of the outer surface of each of the cold packs is well above freezing.
Accordingly, it would be highly desirable to provide an improved cold pack which would, after being exposed to ambient temperature, maintain a low temperature for an extended period of time.
Therefore, it is a principal object of the invention to provide an improved apparatus for abstracting heat from a solid, liquid, gas or other substance.
A further object of the instant invention is to provide an improved cold pack which will maintain a cold temperature for an extended period of time after being exposed to a temperature greater than that of the cold pack.